upgrade-cleanup

# Upgrade Cleanup Skill

Companion to the `rails-upgrade` plugin. Runs the cleanup pass that removes dual-boot scaffolding and aligns the codebase to the new version baseline.

When activated, follow the workflow in `workflows/upgrade-cleanup-workflow.md` end-to-end. **Before any destructive step, confirm direction with the user** (Phase 0 Step 1): are they keeping the **next** version (finishing the upgrade) or keeping the **current** version (abandoning or pausing this hop)? Every subsequent step branches on that answer. To detect the next version, read the `Gemfile` (look for the `if NextRails.next?` / `else` block; the `next?` branch holds the upgraded-to version) or `Gemfile.next.lock`. Do NOT rely on `Gemfile.lock` alone, since during dual-boot it still pins the current version.

## When to Run

Run when the user has explicitly decided to **end the dual-boot phase** in one of two directions:

- **Keep next**: upgrade is done (final hop or stopping point), drop the `else` / current branches.
- **Keep current**: abandoning or pausing this hop, drop the `if NextRails.next?` / next branches and `Gemfile.next*`.

Either way the previous parallel branch must no longer be needed (no rollback window). Deployment to production is not a hard prerequisite.

## Ownership and Delegations

This skill **owns** the cleanup. Phase 1 below is the step list to follow. The `dual-boot` skill's `workflows/cleanup-workflow.md` is older optional reading; if it drifts from this workflow, this workflow wins.

- **Dual-boot scaffolding removal**: performed here in Phase 1.
- **`load_defaults` alignment**: out of scope. The `rails-upgrade` skill handles this via its `rails-load-defaults` step before cleanup runs.

## Critical Rules

- **Do NOT leave `NextRails.next?` or `NextRails.current?` branches in the tree.** That is the failure mode this skill exists to prevent.
- **Do NOT start removing branches before confirming direction.** Keeping the wrong side throws away the work the user wants to keep. If the user has not stated next vs current, ask.

## Workflow

See `workflows/upgrade-cleanup-workflow.md` for the full process: a pre-flight check, dual-boot scaffolding removal, old-version code retirement, CI and Ruby pin alignment, final verification, and the cleanup PR.

## Reference

- [Finishing an Upgrade, FastRuby.io](https://www.fastruby.io/blog/finishing-an-upgrade.html)
- `workflows/upgrade-cleanup-workflow.md`, full workflow
- The `dual-boot` plugin's `workflows/cleanup-workflow.md`, optional reading for context. This skill's Phase 1 is the step list to follow, do not use dual-boot's version when it conflicts.